Ecological Research最新文献

Understanding the factors that control the structure of soil microbial communities is crucial to predict the responses of terrestrial ecosystems to global change. Microbial biomass, composition, and physiological and nutritional states are known to be influenced by abiotic and biotic factors. However, how they vary and respond collectively to abiotic and biotic factors, particularly in forest ecosystems at the landscape scale, remains unclear. This study applied statistical models to explain variations in soil microbial properties from 18 forest sites covering a wide range of annual temperatures, soil properties, stand ages, and plant leaf traits in the Japanese archipelago. Soil microbial properties were evaluated using phospholipid fatty acid (PLFA) analysis. Our results show that fungal PLFA concentration was mainly explained by soil carbon (C) concentration, whereas bacterial and total PLFA concentrations were predominantly determined by soil nitrogen (N) concentration. The ratio of fungal to bacterial PLFA was best explained by the soil C:N ratio. Most variations in microbial composition and physiological and nutritional states were mainly explained by the mean annual temperature and soil pH. Community-weighted means of plant traits, particularly leaf dry matter content (LDMC), also contributed to explaining the variation in bacterial and total PLFA concentrations as well as physiological and nutritional states indicative of temperature and nutritional stress. These results suggest that abiotic factors and plant traits can shape the microbial community structure in forest soils, and that global warming may affect the soil system by altering the physiological and nutritional states of soil microbes in the Japanese archipelago.

This special issue is a partial compilation of research papers from the 10th International Conference on Acid Deposition “ACID RAIN 2020” conference held in Niigata, Japan in April 2023, focusing on ecosystem responses to air pollution. The Acid Rain Conference series began in 1975, initially addressing the harmful effects of acid deposition on ecosystems. Over time, the research focus evolved from simple acid rain issues to effects of excess nitrogen deposition and saturation in the 1980s, and then to ecosystem recovery studies in the 1990s. Current research examines interactions with climate change and air pollution in developing countries. The special issue contains 11 papers: eight on long-term ecosystem responses, two on plants' role in reducing air pollution, and one technical note on soil sampling in biogeochemical monitoring. The long-term studies, from Japan and Norway, show different regional responses to acid deposition. Japanese forests demonstrate higher acid buffering capacity than Northern European ones, partly due to the composition of volcanic soil. Nordic papers focus on modeling tools, MAGIC (Model of Acidification of Groundwater In Catchments), which has been improved over time to simulate the combined effect of acid deposition and climate change impacts. It is significant that exactly half a century after the first conference, this collection of contemporary papers will be published in Ecological Research. This is because findings from research on biogeochemical cycles in ecosystems related to acid rain should be widely shared among the ecological community, and through this, a variety of audiences should be informed.

The assessment of taxonomic diversity (TD) and functional diversity (FD) in natural gradients, including elevation, has grown over the past two decades, but is still relatively little studied. By studying amphibians in the Brazilian forest areas, this research aims to address critical knowledge gaps about biodiversity distribution, while highlighting the need to conserve this fragile and unique hotspot. Herein, we assessed whether and how environmental predictors explain taxonomic and functional alpha and beta diversities of frogs in a Brazilian tropical forest. Elevation significantly and negatively affected TD and FD, with a monotonic linear decrease of both variables with increasing altitude. We did not detect a significant influence of habitat amount (as measured by proportion of forest vegetation cover) on either TD or FD, probably because we observed minimal variation in habitat amount along the elevational gradient. We found a significant influence of elevation on taxonomic and functional dissimilarity values, predominantly explained by the turnover rather than the nestedness component. Our results highlight the importance of functional traits for understanding frog distribution patterns along environmental gradients. Community-level studies on tropical frogs, especially montane species vulnerable to environmental and climatic impacts, remain limited, posing challenges for conservation and management efforts. The high turnover of species composition and functional roles emphasizes the importance of conserving the entire mountain habitat, including the upper elevations.

The worldwide decline of mangroves, driven by land-use changes, contributes to global carbon emissions. Nevertheless, there is still uncertainty surrounding the effects of mangrove deforestation on carbon emissions. Only a few studies have attempted to quantify its implications for the carbon budget, especially at the landscape level. We conducted a field assessment of carbon stock, losses or emissions associated with the conversion of these ecosystems, along with quantifying the impact of this conversion on the carbon budget using carbon sequestration rates in various types of mangrove ecosystems, including intact and varying ages of naturally regenerated mangroves within the Merlimau–Kuala Sebatu landscape. Results show that the estimated total ecosystem carbon (TEC) stock for clear-cut sites was 149.06 ± 7.56 Mg C ha⁻¹, whereas the TEC stock for intact sites was 280.65 ± 16.92 Mg C ha⁻¹; however, no significant difference was observed (p > 0.05). Using a stock-change approach, the equivalent carbon emissions are 482.93 Mg ha⁻¹ CO₂e. This is among the lowest measured C emissions from land use in the tropics. Remarkably, the landscape-scale carbon budget remained favorable, with a net positive balance of 2835 Mg C yr⁻¹, mainly due to the carbon sink capacity and expansion of natural regeneration of the intact mangrove site (796 Mg C yr⁻¹). Our research identifies a deforestation threshold of 75%, at which the carbon budget approaches neutrality. These findings therefore emphasize the importance of protecting intact forests and managing regenerated mangroves sustainably, as younger mangroves help sequester carbon and reduce deforestation emissions.

Appropriate management of wildlife requires sound knowledge and high-quality data about species distributions, abundance, and trends in numbers. From a legal standpoint, Article 12 of the European “Birds” Directive requires Member States to report on breeding populations sizes. Acquiring such data is difficult owing to the wide distribution of most species and the multispecies nature of surveys. We relied on a stratified two-stage spatial sampling design to assess breeding population size of waterbirds in European France. The data come from 2428 grid cells of 500 m × 500 m surveyed by territory or spot mapping three times at one-month interval between 15 March and 15 June during the springs of 2021 or 2022. Individual bird location within each grid cell and their breeding behavior were recorded. A total of 6938 grid cell visits were undertaken, yielding 64,731 observations accounting for 132,292 individuals. These data are primarily aimed to assess the breeding population size of the 25 most common waterbirds (the population size estimates will be presented in a future article). However, because the location and time of observation of all individuals, as well as their behavior, are recorded, questions such as intra- and interspecific distribution rules, or habitat selection processes, can be addressed with this dataset too. As observers were also incited to record all other species among Anatidae, Rallidae, Charadriiforms and Podicipediforms, this dataset also provides robust original data on exotic and rare birds. The detailed Metadata and complete data set are available in MetaCat in JaLTER at https://jalter.diasjp.net/data/ERDP-2025-02.

Describing the population abundance of species remains a fundamental challenge in ecology, particularly in soil ecosystems. While the preferred habitats of moles—top predators in the soil food web—are well documented in open areas such as cultivated lands and grasslands, few studies have focused on mountain forests, where assessing mole abundance is complicated by thick layers of plant leaf litter and complex topography. Additionally, many monoculture conifer plantations in Japan are poorly managed, potentially resulting in compacted soil that is less suitable for moles compared to natural broad-leaved forests. Here, we aimed to quantify the relative abundance of the lesser Japanese mole (Mogera imaizumii) in the mountain forests of Yamagata, Japan, by carefully searching for mole tunnels along 29 census routes (unpaved mountain trails) over 7 months. Although tunnels were detected on most routes (75.9%) regardless of forest type, tunnel density (tunnels/km) was lower in cedar (Cryptomeria japonica) plantations than in natural oak forests. The variation in tunnel density was positively related to earthworm biomass, highlighting the importance of earthworms as a food source. Lower earthworm biomass was associated with either higher soil hardness or higher soil moisture; however, only soil moisture tended to be higher in plantations. As cedars are typically planted in moist environments, the reduced mole abundance in these plantations may be related to the specific soil conditions of cedar plantations. These results demonstrate that mole abundance varies significantly across forest sites in response to soil environments.

We employed stable isotope ratio analysis to quantitatively assess the feeding behaviors of individual macaques within a wild group of Japanese macaques (Macaca fuscata). The primary objective was to evaluate macaque's feeding habits at the individual scale and to clarify the relationship between feeding habits and social factors, including age, sex, and social rank. The study population consisted of the Main group of Japanese macaques on Koshima Island. We collected 78 body hair samples and 29 food resource samples for isotopic analysis. The variability in carbon, nitrogen, and sulfur isotope ratios among individuals in the Main group has ranges of 5.5‰, 6.5‰, and 6.8‰, respectively. Furthermore, the Bayesian mixture model revealed that there were individual differences in the utilization of forest-derived (62.3%–90.5%), marine-derived (6.1%–27.6%), and human-derived (1.7%–23.4%) food resources, driven by the effect of sex, rank, and year. These findings particularly emphasize the utility of sulfur stable isotope ratios and demonstrate how the combined use of three stable isotope ratios enables effective analysis of the relationships between Japanese macaques and their food resources. Furthermore, our results provide a valuable opportunity for the advancement of future research that integrates stable isotope approaches with field investigations. This study not only highlights the applicability of sulfur isotope ratios as a tool for uncovering the use of marine resources by primates in other regions but also shows the potential of using isotopic techniques to distinguish human-derived resources, such as wheat, and to develop strategies for managing crop-raiding by macaques.

Soil carbon, phosphorus, and nitrogen are crucial components that influence the stability of herbaceous plant communities in desertified land restoration. However, there is a dearth of data on the variables that impact the stability of herbaceous communities at various stages of restoration. This study investigated the variables of soil and plant communities on desertified land with varying recovery periods (recovery time less than 10 years, 10–20 years, and more than 20 years) to examine the alterations in the stability of herbaceous communities and the influence of soil nutrients on these changes. Our results indicated that the stability of herbaceous communities exhibited a positive correlation with recovery time. Further research suggests that total carbon (TC) and available nitrogen (AN) levels of soil significantly influenced the herbaceous community's stability when the recovery period was less than 10 years. Total nitrogen (TN) and TC levels of soil affected the community's stability when the recovery period ranged from 10 to 20 years. When the duration of recovery surpassed 20 years, available potassium (AK) in soil significantly impacted the community's stability. This suggested that soil nutrients influence the stability of the herbaceous community. Our findings suggest that soil nutrition is a crucial factor in the initial phase of ecological restoration on desertified land. These findings offer empirical evidence for comprehending the stabilizing mechanism of herbaceous communities in desertified land and provide theoretical backing for ecological restoration methods.

Brittle stars are marine invertebrates that often dominate the seafloor. Their global distribution and abundance make them useful as marine environmental bioindicators. Despite their importance, however, there is limited availability of data on brittle star specimens in Japan. In this study, we focused on Sagami Bay, one of the oldest Japanese marine areas for the study of brittle stars, and organized the data from the specimens collected there. This collection included specimens collected between 2005 and 2021, comprising a total of 695 samples, which were identified as 108 species. All data are deposited in the Global Biodiversity Information Facility (GBIF) through the Japan Node of GBIF and are thus accessible via the GBIF portal under the Creative Commons Attribution 4.0 International license. The Metadata for this abstract published in the Data Article section of the journal are available in MetaCat in JaLTER at https://jalter.diasjp.net/data/ERDP-2025-01.

Malayan tapir is the only extant Asian species in the family Tapiridae, which is endangered and threatened by the risk of inbreeding from population structure. To elucidate the demographic and evolutionary history of the tapirs in Southeast Asia (SEA), this study analyzed whole-genome data from 10 individuals for historical effective population size (Ne) inference using sequentially Markovian coalescent (i.e., PSMC, MSMC, MSMC2), folded site frequency spectrum (i.e., Stairway Plot 2), and their hybrid SMC₊₊. The results revealed that tapir Ne ranged from 6000 to 12,000 in the last glacial period but decreased to <2000 in recent times. Genomic analysis and population split time analysis (PSMC and SMC₊₊) supported a population divergence (Fst > 0.25) between the Sumatran and mainland SEA tapirs 10–6 kya. Subsidence of Sundaland and rainforest reduction were the major drivers for Ne decline. The timing of the population split corresponded well with the inundation of the Straits of Malacca to present-day levels by rapidly rising sea levels ~11 kya. The results of this study, as well as contemporary geographical isolation, support the subspecies status of the Sumatran population. This will have implications for the ex-situ conservation practices that may have produced hybrids of the isolated populations.